Final Report

Abstract

this report. In practice we already have an ocean fossil fuel CO2 disposal program of massive proportions. Surface ocean CO2 disposal, that is uptake from the atmosphere by gas exchange with surface ocean waters, is now about 25 million tons of CO2 per day. Until very recently this has been regarded as a great boon to mankind, in permitting growth of fossil fuel use to aid our economy, and ameliorating concerns over possible climate change. However the pH of surface ocean waters has, in spite of the chemical buffering provided by ocean alkalinity, already changed globally by about 0.1 pH units since the beginning of the industrial revolution. And, if "Business as Usual" continues throughout this century, not only may we expect the probability of substantial climate change, but also the certainty that the pH of surface ocean waters will decline to levels that may exert enormous stress on coral reefs world wide. The problem is that on contemporary time scales we are using only a very small fraction of oceanic capacity: the relatively thin surface layer. The rate of ocean deep water formation (or the removal rate of surface ocean waters) is sufficiently slow that it will take thousands of years to achieve this. The mean ventilation age of deep ocean waters is close to 550 years. The question of whether it is wise, or possible, or effective, to limit the atmospheric disposal/surface ocean uptake step, with its attendant global warming, and inject CO2 directly into the deep ocean, thus holding climate change and surface ocean acidity to "acceptable" levels has long been debated. Although direct ocean CO2 sequestration was first proposed over 25 years ago, and many theoretical analyses have been published, it is only in the last 5 years that experimental techniques permittin..